To me, that looks like parts of a siamese fighter fish photoshopped on to an arowana body.

I did a fairly quick-and-dirty look on the internet, seems this picture is the only reference to it. That in itself is fairly suspicious - successful genetic modification of this scale would have some scientific background to it, which will be out there.

i am also trying to figure out the authenticity of this footage but
could not find one. however, asian hobbyist are good in GMO...
their government support such activity and promote it.
(japan, taiwan, singapore, thailand, and malaysia)

It looks like a genetic mutation similar to veil tail oscars and angels. You typically see mutations when crossing domestic to wild species, these mutations happen in the wild but they usually don't survive to adulthood but when found in the tank the mutation can be further investigated and become a potential variant